Consider adding instructions for configuring workspace in the cloud with GitHub Codespaces

There was a student who was in the process of having his personal computer mailed to him and inquired about doing the trainings on a public computer (e.g., at a public library). He didn't end up needing to go down this route but the question is something that could be worth capturing for future trainings.

Expanding the section on [creating the workspace locally](https://github.com/CUAHSI/learning-gitflows-template/blob/main/course_guide_learners_static.md#3-create-a-local-copy-clone) to both cloning the repository locally OR configuring[ GitHub Codespaces](https://github.com/features/codespaces) might be helpful for future trainings, especially if we might start supporting GitHub Codespaces in other CUAHSI offerings. [This link](https://docs.github.com/en/billing/managing-billing-for-your-products/managing-billing-for-github-codespaces/about-billing-for-github-codespaces) contains pricing information on GitHub Codespaces for the free version of GitHub for personal accounts.